What is one of the primary actions of the latissimus dorsi?

The primary action of the latissimus dorsi is adduction of the arm. This muscle is large and covers a significant portion of the back, originating from the lower vertebrae and extending to the upper arm. When it contracts, it pulls the arm down towards the body, effectively facilitating the movement known as adduction.

In addition to adduction, the latissimus dorsi is also involved in other movements, such as extension and internal rotation of the arm, but its role in bringing the arm closer to the body's midline is a key characteristic that makes adduction a defining action of this muscle. Understanding this primary action is essential for recognizing how the latissimus dorsi contributes to various upper body movements during activities such as pulling or rowing.